Root-resistant base layer

Abstract

Described is a multilayered base layer comprising at least one textile layer and at least one copper layer which are joined together by needling, wherein the puncture holes produced in the copper layer by the needling have a diameter of not more than 1 mm, and a process for producing it. Also described is the use of this layer as a starting material for producing bituminized sealing felts and also the use of the multilayered base layer and of the bituminized sealing felts produced therefrom for discharging electrostatic charges.

I claim: 
     
       1. A multilayered base layer comprising at least one textile layer and at least one copper layer joined together by needling, puncture holes produced in the copper layer by the needling having a diameter of not more than 1 mm, and wherein the copper layer is at least one copper foil having a thickness between 5 and 150 μm, a modulus of elasticity between 100 and 150 kN/mm 2  (measured at 20° C.) and a bending stiffness between 30 and 60 kN/mm 2  (measured at 20° C.). 
     
     
       2. The multilayered base layer of claim 1, wherein the textile layer has a basis weight from 80 to 400 g/m 2 . 
     
     
       3. The multilayered base layer of claim 1, wherein the textile layer has a basis weight from 150 to 300 g/m 2 . 
     
     
       4. The multilayered base layer of claim 1, wherein at least one textile layer is a nonwoven web. 
     
     
       5. The multilayered base layer of claim 1, wherein the nonwoven web comprises continuous filaments whose linear density is from 3 to 15 dtex. 
     
     
       6. The multilayered base layer of claim 1, wherein the nonwoven web comprises polyester fibers or filaments. 
     
     
       7. The multilayered base layer of claim 1, wherein the nonwoven web comprises polyethylene terephthalate fibers or filaments. 
     
     
       8. The multilayered base layer of claim 1, wherein the copper foil has a thickness between 10 and 30 μm.